Creation of a blood free surgical field during orthopedic, vascular and plastic surgery has been the standard of care for over 100 years. The initial device was described by Friederich August von Esmarch in 1873 and is still being used today as the Esmarch bandage. In 1908, Dr. Harvey Cushing first described the use of a pneumatic tourniquet to occlude the blood flow into the scalp during brain surgery. Combination of an Esmarch bandage for squeezing the blood away from a limb (exsanguination) and a pneumatic tourniquet to occlude arterial blood flow is currently used in over 90% of limb operations. The use of a pneumatic tourniquet to occlude the arterial blood flow into a limb is associated with a number of side effects and adverse reactions. The side effects and adverse reactions may include tourniquet paralysis, which is transient or permanent nerve damage caused by the mechanical affect of the wide tourniquet cuff on the nerve. (Ochoa at el. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J Anat. 1972; 113(Pt 3):433-55.) In addition, side effects and adverse reactions may include skin lesions, which are skin abrasions or liquid blisters at the site of tourniquet placements (tourniquet burn) and tourniquet pain, which is tenderness at the site where the tourniquet was placed, that may last for days or even weeks.
More recently devices combining the exsanguination effect of the Esmarch and the blood flow blocking of a tourniquet are being used. This new class of devices is called exsanguination tourniquets. This new technology not only acts as a tourniquet, but is also capable of shifting blood from one part of the limb to another or to the central circulation. Exsanguination tourniquets are described in details in U.S. Pat. Nos. 4,848,324 and 7,854,748 which are included herewith as reference. An important aspect of an exsanguination tourniquet is the need to maintain the pressure applied to the limb in a safe range to avoid crush injuries to the tissues beneath it at any point along the limb. At the same time, it is also critical that the pressure applied by the exsanguination tourniquet is sufficient in order to block the arterial blood flow into the limb.